Update handleiding for klant systeem config #8518

Job	Run time
End-to-end tests, chromium	4m 29s
Build and check documentation	1m 53s
End-to-end tests, firefox	4m 49s
Run the Django test suite (main)	21m 29s
End-to-end tests, webkit	4m 23s
Run the Django test suite (elastic)	5m 13s
End-to-end tests, msedge	4m 47s
Check that documentation for configuration steps is up-to-date	0s
Run the Django test suite (openklant)	2m 44s
Run the Django test suite (sequential)	3m 54s
Upload coverage information to codecov	20s
Build (and push) Docker image	1m 52s
	55m 53s

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